Research ArticleTribological Behavior of Mild Steel under CanolaBiolubricant Conditions
A. Shalwan ,1 B. F. Yousif ,2 F. H. Alajmi,2 and M. Alajmi1
1Department of Manufacturing Engineering Technology, Public Authority for Applied Education and Training,Kuwait City, Kuwait2Faculty of Health, Engineering, and Sciences, University of Southern Queensland, Toowoomba, QLD, Australia
New lubricants based on vegetable oil were developed in this study. Different blends of canola oil mixed with fully synthetic twostock engine oils were developed (0, 20%, 40%, 60%, and 80% of synthetic oil). )e viscosity of the prepared blends was de-termined at different temperatures (20°C–80°C). Tribological experiments were conducted to investigate the effect of the newlydeveloped oil on the wear characteristics of mild steel material compared with stainless steel when subjected to adhesive wearloading. )e weight loss (WL) and the specific wear rate (SWR) of the mild steel using each of the prepared lubricants weredetermined. Scanning electron microscopy was used to examine the worn surface of the mild steel. )e results revealed that purecanola oil as a lubricant performed competitively against a blend of 80% synthetic and 20% canola oils. )e viscosity of the canolaoil and its various blends with synthetic oil are controlled by the environmental temperature since an increased temperaturereduces the viscosity. Also, the experimental results revealed that operating parameters play the main role in controlling the wearbehavior of mild steel since increasing the sliding distances increases the weight loss.)e specific wear rate exhibited a steady stateafter about 5 km sliding distance, and different blends influenced the applied loads and velocity differently. )e mixing ratio ofcanola and syntactic oil was not particularly significant since the pure canola oil exhibited competitive wear performancecompared with the blends. However, an intermediate mixing ratio (40%–60% synthetic oil mixed with 60%–40% canola) canproduce a slightly low specific wear rate among other things.
1. Introduction
Recently, major concerns have emerged over the increasinguse of conventional fossil fuels in industrial products andapplications. )e use of vegetable oil, an important dis-covery, has been the focus of many contemporary techno-logical and industrial researchers. Many studies haverecently explored the possibility of using vegetable oil as alubricant. )e results are promising; vegetable oil has a goodchance of being a better alternative to mineral oil botheconomically and environmentally [1–4]. In the contem-porary world, biodiesel has continually received great at-tention as being an alternative biodegradable and nontoxicrenewable source of fuel. Besides, in the industrial world, theattention has further been shifted with the potential use of
this invention for lubrication. Initially, petroleum by-products were the only ones used for lubrication [5]. )is is,however, a thing for the past. )e emergence of the use ofvegetable oil has inspired the extension of this knowledge tothe extent that recent discoveries show that it is a betteralternative for conventional lubricants. Conventional lu-bricants having numerous advantages have their share ofdisadvantages [6]. )e fact that conventional fossil fuelpetroleum is in abundance is worth noting. However, thisshould not bling one to the fact that this fuel is exhaustible[7]. )is introduces a new twist in the large-scale applicationof lubricants. Biodiesel, being the better alternative, con-tinues to show unending promise as researchers investmillions of dollars to try and implement biodegradablealternatives.
HindawiAdvances in TribologyVolume 2021, Article ID 3795831, 13 pageshttps://doi.org/10.1155/2021/3795831
)e application of vegetable oils for the lubrication ofmachinery has been applied for ages. However, much at-tention shifted the moment cheaper and more availablealternatives were found [7]. )is attention has since beenrefocussed due to the continued shrinkage of oil fields.Vegetable lubricants have been majorly motivated by theneed to conserve the environment. )e next decade is likelyto experience the use of biodegradable greases and lubesthan it has been in anymoment of history. Great controversyhas recently emerged on ways to involve vegetable oils inindustry and manufacturing. Recent technological and en-gineering studies have pointed to the possibility of vegetableoil replacing fossil fuels, not just because of its numerousinherent advantages but also because it is environmentallyfriendly [8, 9]. In today’s world, biodiesel has always beenpaid much attention as an alternative biodegradable andnontoxic renewable source of fuel [7]. Moreover, the in-dustry has also moved to consider the possible use of bio-diesel for lubrication. Initially, petroleum by-products werethe only sources of lubricants [5]. But it is very uncertainwhether vegetable oils outdo conventional lubricants in allrespects. Despite being a renewable source of lubricants andhaving the advantage in environmental conservation, theirdemerits cannot be overlooked. For example, it is chal-lenging to modify these lubricants due to issues of viscosityand structural alteration. )is is why researchers have in-vestigated this vast field in the hope of improving greensources, given their promise as the next generation of lu-bricants in the field of tribology [10].
In current engineering technologies, especially me-chanical engineering, sliding and rolling surfaces are amongthe most important topics to study. In designing machineelements, it is essential to understand the principles oftribology [11]. When two flat-looking surfaces are broughtinto contact, their surface roughness causes points on thetwo surfaces to make contact in different places, creatinginterfacial adhesion. )en, friction occurs when the twobodies try tomove in relation to each other [12]. Due to thesefriction forces, one or both surfaces experience the wear orremoval of material. If this continues for a long time, thedimensions of the mechanical parts are altered and themachine’s functionality is reduced [13].
Industries and researchers are searching for alternativerenewable sources of lubricants to be used in place of fossiloils. Biobased lubricants have many properties that givethem an advantage over petro-based lubricants, but they stillhave some undesirable properties which make petro-basedlubricants preferable for many applications. Research hasbeen done to improve the quality of physical attributes andreduce the cost of using biobased lubricants so as to competewith petro-based lubricants [14]. )ere are now policies toimprove the use of biobased lubricants, but the perceptionand allocation of land for this purpose still create problems.Countries cannot completely change from petro-based lu-bricants to biobased lubricants overnight. )is must be agradual process that requires support from the government,agriculture, research, and industry. Due to the rapid eco-nomic growth in Asia alone, the world demand for lubri-cants has greatly risen [15]. Nagendramma and Kaul [15]
report that the demand for lubricants is predicted to increaseby 1.6 percent annually for at least another three yearsbeyond the current demand of 40 million tons. Even thoughthe consumption is so high, only a small percentage is beingrecycled. So, the need arises to find a renewable alternative tosatisfy the growing need. Biobased lubricants are of limiteduse, but they can be applied in several environmentallysensitive industries such as agricultural machines and othertypes of machinery used under or very close to water re-sources. )e reasons for this are that they are nontoxic andcreate a very small disturbance to the ecosystem.
)e biggest difficulty for research in the development ofbiolubricants is to enhance their physical characteristicswithout damaging their biodegradable, tribological, andenvironmental properties. Controlling behavior consists ofthe following aspects: control of their hydrolytic stability,their physicochemical characteristics, their environmentalcharacteristics, their compatibility with materials and seals,the temperatures when they are used, and their oxidativestability [16]. Researchers have explored biodiesel tribo-logical issues for close to three decades now. Seen from aquantitative point of view, the amount of metal gives thevarious engines their component of wear and tear. )equantitative analysis tries to give a likely source of themetals.)e lubricity issue is central. )e introduction of low sulfurdiesel fuels by regulators in countries such as the UnitedStates has led to the failure of several engine parts such asinjectors [17]. )is is because the pumps and the injectorsare lubricated by the same fuel.
In comparison to fossil fuels, the primary problem withbiodiesel is the concern about viscosity [17]. Viscosity is notaffected, and any effort to modify tribological compoundviscosity leads to substantial changes in lubricant structureand effectiveness. )ese lubricants are sensitive in that anysmall change in structure affects and reduces the effective-ness of these substances. It is proved that it is very difficult tomake the tribological compounds more useful whileavoiding any alteration in their structure [18] because thebalance between these outcomes is delicate.
Vegetable oil types are numerous, and canola oil is one ofthe most important types. It is available all around the worldand it is not expensive. In Canada today, canola oil is thethird most important product [19]. It can be blended withother oils, which makes it one of the best lubricants. Canolaoil is rich in oleic and linolenic acids which lead to a healthierlife.
Canola oil is considered a very healthy oil due to its fattyacid composition. It averages about 60% oleic acid (C18 :1),20% linoleic acid (C18 : 2), and 10% ALA (C18 : 3) [20].Canola oil is extracted from the seeds of the canola plant.)is plant was developed by plant breeders from therapeseed oil plant since rapeseed oil was risky for human andanimal health [21] because of its high proportion of erucicacid. A significant quantity is present in the animal feedmade from rapeseed oil, known to inhibit animal growthrates when taken with high quantities of glucosinolates.Hence, plant breeders embarked on the development ofrapeseed plant types with a low content of erucic acid, lowerucic acid rapeseed (LEAR), and also low in glucosinolate
2 Advances in Tribology
[22]. For marketing purposes, rapeseed plant breeders inCanada named LEAR ‘canola’. With its low levels of erucicacid, glucosinolate, and saturated fats, LEAR (canola oil)appealed to health-conscious consumers and increased thedemand for it. )e production of canola oil has increaseddramatically since World War II.
Canola is also utilized in industry to produce biodiesel, atype of biofuel used for automotive engines. Besides beingused to produce biodiesel [23], canola oil was also utilized tocreate a range of consumer and industrial goods, includinglubricants, due to its nontoxicity [23].
2. Methodology
2.1. Selection and Preparation of Materials. In this study,different blends of vegetable oil were mixed with fullysynthetic oil. )e blend consisted of different proportions,e.g., 20%, 40%, 60%, and 80% of synthetic oil supplementedas necessary by vegetable oil. In this work, canola oil andfully synthetic Castrol oil for two-stroke engines representthe vegetable oil and the synthetic oil, respectively (seeTable 1). )e specifications of the selected canola oil andfully synthetic oil are given in Tables 2 and 3.
To get a homogeneous mixture of lubricants, the syn-thetic oil had to be poured properly on the vegetable oil,which was heated to 50°C. An electrical mixer at a very lowspeed was also employed to achieve a good blend.
2.2. Tribology Machine and Experimental Procedure. In thisstudy, the wear characteristics of mild steel samples wereexamined under ambient conditions (humidity � 50% ± 5,temperature � 25°C) and wet contact against a stainlesssteel counterface (AISI 304, Ra (“roughness average”) �
0.1 μm, hardness � 1250 HB). )e tribological character-istics of the samples were studied applying the BOR(“block on ring”) method, with a newly built machinedesigned to handle this technique as shown in Figure 1[26]. )e most essential components of the tribologymachine are the container filled with the various mixesand the arm attached to the container that provides theload for the samples. A sliding distance of 0–10 km, slidingspeed of (0–2m/s), and the applied load of (10 to 20 N)were maintained in the experiments.
)ree samples for each set were tested, and the averagefor each set was determined and the load cell was cali-brated. It should be mentioned here that several attemptshave been adopted to get the precise procedure. )esamples were weighed, dried, and cleaned prior to theoperation of the machine. )e specimens were thenmounted on the machine holder, the timer, and the loadcell reader set to zero before testing at the necessary loaddistance. )e samples were weighed, dried, and cleanedafter the test. )e variation in sample weight was calcu-lated. )e loss of wear volume was determined employinga weighing scale of ±0.1 mg as a result of the WL of eachsample. Equation (1) was used to determine SWR. )eaverage measurement of each dilution of canola oil wasdetermined three times for each test.
SWR �Δw/ρL × D
, (1)
where Δweight�weight (before)−weight (after), ρ is thesample density, L is the applied load, and D is the slidingdistance.
)e prepared mixture’s viscosity was calculated using a“Viscometer” in the “University of Southern Queensland”.Several oil temperatures were taken into account(10°C–80°C). “Scanning electron microscopy” was employedto analyze the worn surfaces of the samples of mild steel.)ismicroscopy is labeled as “Joel” which belongs to the“University of Southern Queensland”.
3. Results and Discussion
In this section, the results will be addressed of testing theviscosity of different blends at different temperatures, thewear data from tribological applications, and the surfacecharacteristics of mild steel treated with tested with differentblends and applications. Each parameter and its effect onaspects such as the surface and wear of mild steel are dis-cussed hereinafter.
3.1. Blends’ Viscosities. )e viscosity results of the preparedblends at different temperatures as measured with a Vis-cometer are shown in Table 4. )e results show the rela-tionship between the temperature in °C and Viscosity inCp≈MPa for four blends after applying heat from 10°C to80°C.
Table 4 reveals that the viscosity of all the blends sig-nificantly depends on temperature. In other words, theresults state that viscosity is reduced as temperatures in-crease. )e table demonstrates that the rise in the syntheticpercentage also rises the viscosity. )e additive syntheticappears to stabilize and increase the viscosity in the preparedmixture because of the presence of the lubrication additives.)is rise in viscosity with the adding of synthetic oil may bebecause of the fact that the synthetic oils include additiveslike EVA which may substantially enhance viscosity, asstated by Quinchia et al. [27].
3.2. Wear Behavior of Mild Steel Lubricated by Pure CanolaOil. Figure 2(a) displays the WL in samples from mild steelto sliding distances when lubricated by pure vegetable oil.)e figure illustrates that any rise in the sliding distance risesthe WL.)is phenomenon may be described by the fact thatthe rise in the sliding distance rises the material eliminationfrom the soft rubbing port surface which in this case is mildsteel. )is result has been demonstrated by many articlessuch as [28, 29]. )e sliding distance linearly increases theWL, as is well known, given the process of integration andadoption between the rubbed surfaces, [30]. To explain thisfurther, the wear data are signified by a different type ofwear, the SWR against the sliding distance. )e SWR in-dicates the volume loss by the materials in terms of appliedsliding distance and load. )is can help to clarify the use ofsliding surfaces when the rubbing time or the sliding
Advances in Tribology 3
distance rises. Figure 2(b) shows the SWR against the slidingdistance of mild steel lubricated by pure vegetable oil. )eSWR begins at a high level and subsequently declines.However, as the sliding distances increase, the decline in theSWR value is not so marked. A technique is carried outduring the initial step of the rubbing process. In other terms,the two surfaces are adopting one another for greater surfaceintegration. With further sliding (over 5 km), the SWR issteadily lower which represents the steady state of therubbing procedure. In other terms, the material eliminationremains constant corresponding to the sliding distance. Itmust be noted that the “steady state” of the specified wearrate is the value that the designer takes into account in theproduction of components.)is is a frequent trend in metalsand polymers because the interface or rubbed surfaces arenot very much modified while sliding. )is behavior by twodifferent types of steel has recently been reported [31, 32].
)e SWR of mild steel versus sliding velocity is createdand shown in Figure 3(a) to illustrate the impact of a slidingspeed on the wear performance of mild steel. )is figuredemonstrates that the SWR against the counterface speed ofmild steel lubricated with pure vegetable oil is high when thevelocity is at a low level.
From the viscosity data presented in Table 4, it seemsthat the pure canola oil velocity is low. In other terms, during
the sliding, not enough is being lifted to the surfaces. At highspeed, however, pure canola oil may separate the mildstainless steel from the stainless steel counterface at a certainlevel, resulting in poor material removal.
To show the influence of the sliding speed on the wearbehavior of the mild steel, the specific wear rate of the mildsteel against sliding velocity is generated and plotted inFigure 3(a). In Figure 3(a), the specific wear rate against thespeed of the counterface on mild steel under the purevegetable oil lubricant condition shows that the specific wearrate is high at the level of low velocity. From the viscositydata presented in Table 4, the velocity of the pure canola oil islow. In other words, there is not enough lifting to thesurfaces during the sliding. However, at high speeds, thepure canola oil can separate the mild steel from the stainlesssteel counterface at a certain level which resulted in lowremoval of materials.
)e influence of the applied load lubricated by purevegetable oil on the SWR is demonstrated in Figure 3(b).)is figure shows that the SWR decreases with a load in-crease from 100N to 140N and then increases with anintermediate load value of 180N and then a sudden dropwith a very high load of 200N. )e rise in applied load mustbe indicated here as a proportional relationship of the weightloss to the material removed. However, it is extremelydifficult to connect this with the relationship between theSWR as well as the applied load. )ese scattered measure-ments of the SWRwere prevented by numerous writers, whopresent the data in terms of WL (such as [33]), or volumeloss (such as [34]). In contrast, Chin and Yousif [35] havefound comparable scattered values of SWR when testingpolymeric composites against stainless steel under variousapplied loads. From this evidence, the findings of the tests inthe present research agree with those in the currentliterature.
3.3. Wear Behavior of Mild Steel Lubricated by 20% of Syn-thetic Oil and 80% of Canola Oil. )is section is identical tothe above except that the lubricant properties could beexpected to be different because the findings in this sectionare produced by amixture condition of 80% of canola oil and20% of synthetic oil. )e findings are given in the same wayas those of the previous section. In other terms, wear testresults are studied under various operating conditions. Withrespect to the loss in weight versus the sliding distance,Figure 4(a) illustrates theWL versus sliding distance on mildsteel lubricated with a mixture of 80% of canola vegetable oiland 20% of synthetic oil. )e WL trend is like the trendshown by the pure canola oil as a lubricant because an
Table 1: Blend oil percentage.
Blend Percentage of canola Percentage of fully synthetic Castrol oil1 100 02 80 203 60 404 40 605 20 80
Table 2: Canola oil specification [24].
Parameter ValueRelative density (g/cm3; 20°C/water at 20°C) 0.914–0.917Cold test (15 hours at 4°C) Passed)ermal conductivity (W/m°K) 0.179–0.188Refractive index (nD 40°C) 1.465–1.467Smoke point (°C) 220–230Viscosity (kinematic at 20°C, mm2/sec) 78.2Specific heat (J/g at 20°C) 1.910–1.916Crismer value 67–70Flash point, open cup (°C) 275–290″
Table 3: Fully synthetic oil specification [25].
Colour Deep redBase number 2.5Sulfated ash, mass% <0.10Flash point 94Biodegradability, OECD 301B, % 64Viscosity index 175Density at 15°C, kg/L 0.895Viscosity, kinematic, cStAt 40°C 39At 100°C 7.8
4 Advances in Tribology
increase in sliding distance raises the accumulatedWL in thepreceding section (see Figure 3(a)). )is is fully described inthe preceding section, where the removal of material is in aproportional ratio to the sliding distance and is explainedand approved in the literature. However, it would be notedhere that the difference between this result and the precedingone is that the viscosity of the lubricant is greater now thanbefore, which could have impacted the values of wear.
To display the SWR for the mild steel lubricated with 20percent of synthetic oil mixed with 80 percent of canola inconnection with the sliding distance, Figure 4(b) is plotted.)e SWR rises with the rise of the sliding distance.)is is notthe typical depiction with sliding distances of the SWR. )etypical pattern is a rise followed by a drop and then a steadystate. It seems that the major problem to raise here is the lowSWR on small sliding distances. )is may be primarily
1 2 35
4
Figure 1: )e Tribo-test machine. 1� counterface, 2�BOR-load lever, 3� dead weights, 4�BOR-specimen, and 5�BOR-load cell.
Table 4: Viscosity findings for different percentage blends at various temperatures.
Figure 2: (a) Weight loss and (b) SWR versus sliding distance of mild steel lubricated by pure vegetable oil.
Advances in Tribology 5
because of the greater viscosity of the mixtures as comparedto pure canola, which indicates the common trend of theSWR in relation to sliding distance (Figure 3(b)). Never-theless, the mild steel was coated with lubricant at the initialstage of the rubbing resulting in a drastic high reduction ofthe material removed. )is action has been reported by MatTahir et al. [36] describing a PKAC–E (“palm kernel acti-vated carbon–epoxy”) composite tested at high temperature.In his study, he provided the presence in the interface of athird body as the cause for the rise in the SWR, and the samereason may also account for the present results.
Figure 5(a) indicates the impact of the sliding speed onthe SWR of the mild steel lubricated by a 20 percent syn-thetic mixture. As with the previous data concerning purecanola oil (Figure 3(a)), a drop in the SWR is shown withevery rise of the velocity. )e primary reason is that morelubricant is on the interface at a higher speed.
In the preceding section, the applied load influence onthe SWR was not significant, as the data were scattered
(Figure 3(b)).)e SWR versus the load applied to mild steelslubricated by a blend of a 20 percent SN as well as purecanola oil reveals the same trend as the previous one as inFigure 5(b). )e discussion in the last part is identical to theone given here. Despite these variations in the data, thechanges in the SWR are very small, a power of 10−8. In acomponent design, it could be stated that no effect can betraced on the mild steel wear performance on the appliedload because this is not a noticeable change in SWR values[37].
3.4. Wear Behavior of Mild Steel Lubricated by 40% of Syn-thetic Oil and 60% of Canola oil. )is section discusses thewear behavior of mild steel with a 40% synthetic oil mixturein a lubrication state. Figure 6(a) shows the materials re-moved during the rubbing process from the mild steel whenlubricated by a blend of 40 percent of synthetic oil over asliding distance. Similarly, to previous linked sections, the
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Figure 4: (a) Weight loss and (b) SWR of mild steel versus sliding distance lubricated by a blend of 20% of synthetic oil and 80% of canolaoil.
6 Advances in Tribology
weight loss of mild steel rises with a rise in the slidingdistance owing to the first removal from the surface of thematerial, when pure canola (Figure 2(a)) and a synthetic oilmixture of 20 percent were used (Figure 4(a)). It should benoted here that the rubbed surfaces in the early stage havetips that may be eliminated (high loss in weight) easily andthat sometimes the surfaces undergo pure adhesive wear.Scherge and Linsler [38] thoroughly discussed and describedthis step in the testing under lubricant contact circumstancesof various metal-metal contacts. However, in that study, theprimary emphasis was on the run-in stage, which mayprovide a similar interpretation in relation to the frictioncoefficient.
Figure 6(b) displays the SWR against the sliding distanceof mild steel lubricated by a 40 percent SN as well as purevegetable oil blended. )e figure indicates variations in the
SWR value; however, it must be noted that variation in termsof value is extremely small, as the range of the SWR isapproximately ±0.25 10−8. As already stated in Section 3.3,this quantity can safely be ignored in the design of thecomponent. In other words, it can be said that the slidingdistance has a very minor influence on the SWR of the mildsteel. )is may be because of the increased proportion ofsynthetic oil compared to the blend in earlier sections. Someadditives such as EVA serve as coating agents in synthetic oilto inhibit material removal.
Figure 7(a) introduces the SWR against the counter-face sliding speed on mild steel lubricated by a 40%percent synthetic oil mixture. )e SWR starts high andthen decreases. Generally, the figure indicates that the riseof the sliding velocity leads to a decrease in SWR. )etrends in the SWR in the connection to velocity are similar
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Figure 6: (a) Weight loss and (b) SWR of mild steel versus sliding distance lubricated by a blend of 40% synthetic oil and 60% canola oil.
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to those shown in this section in the 40 percent syntheticoil mixture in Figures 3(a) and 5(a) for pure canola andsynthetic oil mixture lubricants of 20%. Likewise, the risein velocity encourages the lubricant to flow over the in-terface where the lubricant acts as a separating agent. Yet,very small amounts of materials are removed, amountingto 10−9 value. Figure 7(b) presents the SWR versus theload applied on the mild steel lubricated by a 40 percentsynthetic oil mixture. )e SWR begins to be high and thendrops to a low level. However, when we determine theweight loss only, a rise in the applied load rises the re-moval of materials. )e SWR is reduced in terms ofmaterial removal in relation to the applied load values.)e drop value is approximately10−10 mm3/N.m.
3.5.WearBehavior ofMild Steel Lubricated by a 60%SyntheticOil and 40% Canola Oil Blend. Figure 8(a) illustrates thesliding distance versus weight loss onmild steel lubricated by60 percent synthetic oil mixed with 40 percent canola oil.Essentially, the increase in the sliding distance results in anincreased WL. )e linear relationship between WL and thesliding distance is evident in this figure, which resemblesthose exhibited before involving pure canola, a 20 percentsynthetic mixture, and a 40 percent synthetic mixture. )ereason for this behavior is discussed in depth in previoussections.
Figure 8(b) shows the SWR versus the sliding distanceof mild steel lubricated with 40 percent pure vegetable oiland 60 percent SN blend. )e SWR starts at high and thenmaintains a steady state. )is behavior is common of allthe substances that manifest high material eliminated inthe 1st phase, the running-in interval, by following asteady state that presents the efficiency of the mild steel forlong periods when lubricated by this blend. From thisfigure, the SWR of the mild steel is equivalent to 310−9 mm3/N.m at the steady stage after approximately5 km sliding distance or more.
Figure 9(a) introduces the SWR versus the velocity of thecounterface on mild steel lubricated by a 60 percent syn-thetic oil mixed with 40% canola oil. )e SWR is fluctuating.In comparison to previous findings for pure canola, 20percent synthetic, and 40 percent synthetic lubricants, the 60percent of synthetic oil illustrates an unremarkable impacton the SWR of the mild steel with respect to velocity. )ismay be caused due to a variety of factors, like the dirtthickness, lubricant adherence to the surface, or debriswashing on the interface. On the basis of the available data,the high viscosity of this mixture is the main cause con-trasted with the low proportion of syntactic oil in othermixtures. )e high-velocity oil enters the interface andperforms an important role in cooling down the area car-rying the debris or/and spreading it over the surface.
Figure 9(b) presents the SWR against the load applied onthe mild steel lubricated by 60 percent synthetic oil. Like thepreceding trends in pure canola, the applied load for thiscombination is 20 percent of synthetic oil and 40 percent ofsynthetic oil.
3.6. Wear Behavior of Mild Steel Lubricated by 80% of Syn-thetic Oil and 20% of Canola Oil. )e wear findings of themild steel sliding versus the counterface of the stainless steellubricated by 80 percent synthetic oil mixed with 20 percentcanola oil are shown in Figures 10 and 11 in various op-erating conditions. In regard to weight loss, Figure 10(a)displays the WL versus sliding distance on mild steel lu-bricated by an 80 percent synthetic oil mixture. Generally,the increase of sliding distance leads the weight loss to rise.)is is a trend similar to those demonstrated before whenvarious mixtures were employed; the rise in WL is a well-known phenomenon.
Regarding the sliding distance effect on the SWR,Figure 10(b) shows the SWR versus the mild steel slidingdistance lubricated by an 80 percent synthetic mixture.)e SWR range may be observed at approximately 8
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Figure 7: SWR of mild steel lubricated by a 40% synthetic and 60% canola oil blend against (a) speed and (b) load.
8 Advances in Tribology
10−8 mm3/N.m. )e change in the SWR is in a range of ±210−8 mm3/N.m. )e substantial effect of the sliding dis-tance on SWR cannot be seen. It may be suggested that thecause for this is the high viscosity of the blend, whichconsists of 80% synthetic oil, introducing a higher vis-cosity than any previous blend. At their high viscosity, theability to separate mild steel and stainless steel on tworubbed surfaces is greater than separating those at thelow-viscosity surfaces.
Figure 11(a) represents the SWR versus the counterfacesliding velocity on mild steel lubricated by 80% of syntheticoil blended with 20 percent of canola oil. Generally, it may beobserved from this figure that a rise in velocity increases theSWR. It was noted that the lubricant utilized to gain thisresult is highly viscose. )e high viscosity related to highinterface speed may exert an adverse effect on the material’swear rate [39, 40].
Figure 11(b) shows the SWR versus load applied to mildsteel lubricated by the 80 percent synthetic oil mixture. )erise in the applied load displays a reduction in the SWR; thisbehavior was shown earlier by mild steel under the con-ditions imposed by other mixtures. )e cause for this isdescribed above.
3.7. Influence of Synthetic Oil on Wear Behavior of the MS.To display the” impact of various mixtures on the SWR ofthe mild steel due to an optimized “mixing ratio”, the SWRversus the mild steel sliding distance lubricated by all kindsof mixtures is shown in Figure 12. It may be said that thefindings for all the blends here are comparable. )e purecanola vegetable oil displays intermediate behavior com-pared to synthetic oil, particularly under steady-state con-ditions. )e combination of the two oils appears to havedistinct effects as the low synthetic oil percentage sub-stantially improves the lubricant characteristics of the oil,resulting in the lowest SWR of all. But adding a high per-centage of synthetic oil worsens the lubricant characteristicsthat indicated a high removal of materials from the mildsteel.
3.8. Scanning Electron Microscopy Observations.Figures 13–15 show the surface morphology of the surfacesworn with mild steel. )ey were tested using various lu-bricants at 2m/s sliding velocities, 10 km sliding distance,and 20N applied load.
In the condition of pure canola oil lubricant(Figure 13(a)), pure adhesive wear seems to be a smooth
0
2E-10
4E-10
6E-10
8E-10
1E-09
1.2E-09
1 1.25 1.5 1.75 2 2.25
SWR
(mm
3/N
·m)
Speed (m/s)
(a)
0.00E+00
1.00E-10
2.00E-10
3.00E-10
4.00E-10
5.00E-10
0 5 10 15 20 25
SWR
(mm
3/N
·m)
Load (N)
(b)
Figure 9: SWR of mild steel lubricated by 60% synthetic and 40% canola oil blended against (a) speed and (b) load.
0
0.00025
0.0005
0.00075
0 2.5 5 7.5 10 12.5
Wei
ght l
oss (
mg)
Sliding Distance (km)
(a)
0
2E-09
4E-09
6E-09
8E-09
0 2.5 5 7.5 10 12.5
SWR
(mm
3/N
·m)
Sliding Distance (km)
(b)
Figure 8: (a) Weight loss and (b) SWR of mild steel against sliding distance lubricated by the 60% synthetic and 40% canola oil blend.
Advances in Tribology 9
surface. )is shows the removal of few materials from themild steel surface, which supports the findings provided inFigure 12. Low-viscosity oil may assist in heat reduction inthe interface and debris washing [41, 42]. On the other hand,
Figure 13(b) displays the 20 percent synthetic oil mixed with80 percent canola utilized as the lubricant is an indication ofthe abrasive nature of the mild steel surface. )is may en-courage the concept that increasing the viscosity of the
0
0.005
0.01
0.015
0 2.5 5 7.5 10 12.5
Wei
ght l
oss (
mg)
Sliding Distance (km)
(a)
4E-08
5E-08
6E-08
7E-08
8E-08
9E-08
0.0000001
1.1E-07
1.2E-07
0 2.5 5 7.5 10 12.5
SWR
(mm
3/N
·m)
Sliding Distance (km)
(b)
Figure 10: (a) Weight loss and (b) SWR of mild steel against sliding distance lubricated by the 80% synthetic and 20% canola oil blend.
0
2.5E-09
5E-09
7.5E-09
1E-08
1.25E-08
1.5E-08
1.75E-08
1 1.25 1.5 1.75 2 2.25
SWR
(mm
3/N
·m)
Speed (m/s)
(a)
0.00E+00
7.50E-09
1.50E-08
2.25E-08
3.00E-08
5 10 15 20 25
SWR
(mm
3/N
·m)
Load (N)
(b)
Figure 11: SWR of mild steel lubricated by an 80% synthetic and 20% canola oil blend against (a) speed and (b) load.
0
2E-09
4E-09
6E-09
8E-09
1E-08
1.2E-08
0 2.5 5 7.5 10 12.5
SWR
(mm
3/N
·m)
Sliding Distance (km)VG-Oil 100%60% VG & 40% SY
80% VG & 20% SY40% VG & 60% SY
Figure 12: SWR behavior versus sliding distance for the effect of different blends on the mild steel.
10 Advances in Tribology
lubricant allows the debris to be carried away and enters theinterface by adding the synthetic oil. In other terms, theadhesive wear transfers into an abrasive surface.
Figure 14 exhibits the surface morphology of the wornsurface of mild steel lubricated by 40% synthetic oil and 60%canola oil. Figure 14 shows further abrasiveness similar towhat appears in Figure 13(a). As a higher viscosity lubricantwas utilized to create the worn surface in this figure, itverifies the concept of high viscosity removing debris andtherefore converting adhesive wear into abrasive surfacesleading to the removal of the plentiful material (Figure 12).
Figures 15(a) and 15(b) show the severely abrasivesurface and the mild steel degradation, supposed to becaused by the three abrasive characteristics.
4. Conclusions
)e primary aim of this work was to analyze the canola oilviscosity and its mixtures with various totally synthetic oilratios and to examine the effect of those developed mixtureson the wear behavior of mild steel, rubbed against thecounterface of stainless steel. )e findings showed a
smooth surface
(a)
abrasive surface
(b)
Figure 13: (a) Pure canola oil lubricant and (b) 20% synthetic oil mixed with 80% canola oil.
abrasive surface
Figure 14: 40% synthetic oil mixed with 60% canola oil.
(a) (b)
Figure 15: (a) 60% synthetic oil mixed with 40% canola oil and (b) 80% synthetic oil blended with 20% canola oil.
Advances in Tribology 11
relatively low viscosity of canola oil compared to oils pre-viously examined in the literature like cotton, soy, and palm.However, this may be advantageous for some uses of low-viscosity canola oil, like bushes, slides, and bearings. Someparticular results of this study may be discovered in thefollowing points.
Table 4 evidently shows that the viscosity of all the blendstogether relies upon temperature; that is, the outcomesreveal that viscosity is diminished as the temperature rises.
(1) Mixing canola oil with synthetic oil enhances thelubricant’s viscosity, thus improving its propertiesunder certain circumstances.)e lubricant is capableof spreading the two rubbed surfaces using a lu-bricant layer with high viscosity. However, highviscosity oil may carry away the worn debris, and thisdebris may enter the interface and create three-bodyabrasion, leading to the removal of such material
(2) For the tribological findings, the operating condi-tions have the fundamental charge of regulating thewear performance of the mild steel lubricated by allkinds of blends. Increasing the sliding distancesincreases the WL in all working conditions andmixtures of the mild steel. However, for most of theoperating conditions, the SWR achieved a steadystate after approximately 5 km sliding distance
(3) Regarding the effect of the mixtures on the wear ofthe mild steel, the mixing ratio of canola and syn-tactic oil had no influence, as pure canola oil revealedcompetitive wear performance, as did the variousblends. Yet, the intermediate mixing ratio (40% to60% synthetic oil blended with 60% to 40% canolaoil) generated slightly low SWR compared with theothers
Data Availability
)e tribology data used to support the findings of this studyare included within the article.
Conflicts of Interest
)e authors declare that they have no conflicts of interest.
References
[1] X. Cui, P. Cao, J. Guo, and P. Ming, “Use and performance ofsoybean oil based bio-lubricant in reducing specific cuttingenergy during biomimetic machining,” Journal ofManufacturing Processes, vol. 62, pp. 577–590, 2021.
[2] G. Oncu and E. Durak, “Utilization of waste vegetable oilmethyl esters as lubricant oil,” Proceedings of the Institution ofMechanical Engineers - Part J: Journal of Engineering Tri-bology, vol. 235, no. 10, pp. 2144–2154, 2021.
[3] A. Dhanola and H. C. Garg, “Experimental analysis of theefficacy of vegetable oil-based nanolubricants for improvingjournal-bearing performance,” Proceedings of the Institutionof Mechanical Engineers - Part J: Journal of Engineering Tri-bology, vol. 235, no. 9, pp. 1974–1991, 2021.
[4] A. Shalwan, B. F. Yousif, F. H. Alajmi, K. R. Alrashdan, andM. Alajmi, “Tribological investigation of frictional behaviour
of mild steel under canola bio-lubricant conditions,” Tribologyin Industry, vol. 42, no. 3, pp. 481–493, 2020.
[5] P. K. Sahoo and L. M. Das, “Combustion analysis of Jatropha,Karanja and Polanga based biodiesel as fuel in a diesel en-gine,” Fuel, vol. 88, no. 6, pp. 994–999, 2009.
[6] D. Berthe, D. Dowson, M. Godet, and C. M. Taylor, Tribo-logical Design of Machine Elements, Vol. 14, Elsevier,Amsterdam, Netherlands, 1989.
[7] G. Stachowiak and A. W. Batchelor, Experimental Methods inTribology, Elsevier, 2004.
[8] L. Aguado-Deblas, R. Estevez, J. Hidalgo-Carrillo et al.,“Outlook for direct use of sunflower and Castor oils asbiofuels in compression ignition diesel engines, being part ofdiesel/ethyl acetate/straight vegetable oil triple blends,” En-ergies, vol. 13, no. 18, p. 4836, 2020.
[9] S. Che Mat, M. Y. Idroas, M. F. Hamid, and Z. A. Zainal,“Performance and emissions of straight vegetable oils and itsblends as a fuel in diesel engine: a review,” Renewable andSustainable Energy Reviews, vol. 82, pp. 808–823, 2018.
[10] S. Wen and P. Huang, Principles of Tribology, Wiley OnlineLibrary, Hoboken, NJ, USA, 2012.
[11] G. Stachowiak and A. W. Batchelor, Engineering Tribology,Butterworth-Heinemann, Oxford, UK, 2013.
[12] J. Williams, Engineering Tribology, Cambridge UniversityPress, Cambridge, UK, 1994.
[13] H. Hirani, Fundamentals of Engineering Tribology with Ap-plications, Cambridge University Press, Cambridge, UK, 2016.
[14] A. S. Ramadhas, S. Jayaraj, and C. Muraleedharan, “Use ofvegetable oils as I. C. engine fuels-A review,” RenewableEnergy, vol. 29, no. 5, pp. 727–742, 2004.
[15] P. Nagendramma and S. Kaul, “Development of ecofriendly/biodegradable lubricants: an overview,” Renewable and Sus-tainable Energy Reviews, vol. 16, no. 1, pp. 764–774, 2012.
[16] J. O. Agunsoye, S. I. Talabi, O. Awe, and H. Kelechi, “Me-chanical properties and tribological behaviour of recycledpolyethylene/cow bone particulate composite,” Journal ofMaterials Science Research, vol. 2, no. 2, p. p41, 2013.
[17] C.-Y. Lin, “Strategies for promoting biodiesel use in marinevessels,” Marine Policy, vol. 40, pp. 84–90, 2013.
[18] A. M. Danilov, “Progress in research on fuel additives(review),” Petroleum Chemistry, vol. 55, no. 3, pp. 169–179,2015.
[19] R. C. Rowe, P. J. Shesjey, and S. C. Owen, PharmaceuticalExcipients 5: Single-User Version, McGraw-Hill MedicalPublishing Division, 2005.
[20] V. J. Barthet, “Canola: overview,” in Encyclopedia of FoodGrains, C.Wrigley, Ed., pp. 237–241, Academic Press, Oxford,UK, Second edition, 2016.
[21] L. Day, “Proteins from land plants - potential resources forhuman nutrition and food security,” Trends in Food Science &Technology, vol. 32, no. 1, pp. 25–42, 2013.
[22] A. A. Aachary, U. )iyam-Hollander, and M. N. Eskin,“Canola/rapeseed proteins and peptides,” in Applied FoodProtein Chemistry, pp. 193–218, Wiley, Hoboken, NJ, USA,2014.
[23] N. E. Bassam, Energy Plant Species: @eir Use and Impact onEnvironment and Development, Routledge, London, UK,2013.
[24] R. Przybylski, T. Mag, N. A. M. Eskin, and B. E. McDonald,Canola Oil. Bailey’s Industrial Oil and Fat Products, WileyOnline Library, Hoboken, NJ, USA, 2005.
[25] C. A. Moses and P. N. Roets, “Properties, characteristics, andcombustion performance of Sasol fully synthetic jet fuel,”
12 Advances in Tribology
Journal of Engineering for Gas Turbines & Power, vol. 131,no. 4, Article ID 041502, 2009.
[26] B. F. Yousif, “Design of newly fabricated tribological machinefor wear and frictional experiments under dry/wet condition,”Materials & Design, vol. 48, pp. 2–13, 2013.
[27] L. A. Quinchia, M. A. Delgado, T. Reddyhoff, C. Gallegos,and H. A. Spikes, “Tribological studies of potential vegetableoil-based lubricants containing environmentally friendlyviscosity modifiers,” Tribology International, vol. 69,pp. 110–117, 2014.
[28] G. S. Vasyliev, “)e influence of flow rate on corrosion of mildsteel in hot tap water,” Corrosion Science, vol. 98, pp. 33–39,2015.
[29] X. Zheng, S. Zhang, W. Li, M. Gong, and L. Yin, “Experi-mental and theoretical studies of two imidazolium-basedionic liquids as inhibitors for mild steel in sulfuric acid so-lution,” Corrosion Science, vol. 95, pp. 168–179, 2015.
[30] B. F. Yousif and N. S. M. El-Tayeb, “Wear and frictioncharacteristics of CGRP composite under wet contact con-dition using two different test techniques,” Wear, vol. 265,no. 5-6, pp. 856–864, 2008.
[31] M. Lindroos, K. Valtonen, A. Kemppainen, A. Laukkanen,K. Holmberg, and V.-T. Kuokkala, “Wear behavior and workhardening of high strength steels in high stress abrasion,”Wear, vol. 322-323, pp. 32–40, 2015.
[32] M. Ruiz-Andres, A. Conde, J. de Damborenea, and I. Garcia,“Friction and wear behaviour of dual phase steels in dis-continuous sliding contact conditions as a function of slidingspeed and contact frequency,” Tribology International, vol. 90,pp. 32–42, 2015.
[33] S. A. Alidokht, A. Abdollah-zadeh, and H. Assadi, “Effect ofapplied load on the dry sliding wear behaviour and thesubsurface deformation on hybrid metal matrix composite,”Wear, vol. 305, no. 1–2, pp. 291–298, 2013.
[34] M. A.Wimmer, M. P. Laurent, M. T. Mathew et al., “)e effectof contact load on CoCrMo wear and the formation andretention of tribofilms,” Wear, vol. 332-333, pp. 643–649,2015.
[35] C. W. Chin and B. F. Yousif, “Potential of kenaf fibres asreinforcement for tribological applications,” Wear, vol. 267,no. 9–10, pp. 1550–1557, 2009.
[36] N. A. Mat Tahir, M. F. B. Abdollah, R. Hasan, andH. Amiruddin, “)e effect of sliding distance at differenttemperatures on the tribological properties of a palm kernelactivated carbon-epoxy composite,” Tribology International,vol. 94, pp. 352–359, 2016.
[37] R. G. Bayer, Engineering Design for Wear, CRC Press, BocaRaton, FL, USA, Second edition, 2004.
[38] M. Scherge, D. Linsler, and T. Schlarb, “)e running-in cor-ridor of lubricated metal-metal contacts,” Wear, vol. 342-343,pp. 60–64, 2015.
[39] F. Bowden and E. Freitag, “)e friction of solids at very highspeeds. I. Metal on metal; II. Metal on diamond,” in Pro-ceedings of the Royal Society of London A: Mathematical,Physical and Engineering Sciences, )e Royal Society, London,UK, March 1958.
[40] J. G. Alotaibi and B. F. Yousif, “Biolubricants and the potentialof waste cooking oil,” in Ecotribology, pp. 125–143, Springer,Berlin, Germany, 2016.
[41] J. T. Araruna Jr, V. L. Portes, A. P. Soares et al., “Oil spillsdebris clean up by thermal desorption,” Journal of HazardousMaterials, vol. 110, no. 1–3, pp. 161–171, 2004.
[42] L. Tang, J. Xiong, W. Wan et al., “)e effect of fluid viscosityon the erosion wear behavior of Ti(C, N)-based cermets,”Ceramics International, vol. 41, no. 3, pp. 3420–3426, 2015.
